1. Field of the Invention
The invention relates to a remote control apparatus for a vehicle, and more particularly to a remote control apparatus that can remotely control a vehicle function using a portable device.
2. Description of the Related Art
Keyless entry systems are known. In such keyless entry systems, the doors of a vehicle may be unlocked or locked when the user of the vehicle approaches or leaves. Typically, the key of the keyless entry system transmits a signal to a vehicle to remotely control various vehicle functions. In the keyless entry systems, for example, the user may remotely control vehicle functions such as locking/unlocking the doors, opening/closing the windows or a sliding roof, or even controlling the air conditioner from the outside of the vehicle, using the key. An example of such remote control apparatuses is described in Japanese Patent Application Publication No. JP-A-7-59165 (hereinafter, referred to as “Publication No. 7-59165).
In such remote control apparatuses, if the user inadvertently operates the key at a place remote from the vehicle, the user may be unaware that remote control is executed by inadvertently operating the key. For example, the user may unintentionally unlock the doors by inadvertent operation of the key. In the remote control apparatus described in the Publication No. 7-59165, the operations that can be executed by the key of the keyless entry system are limited based on the distance from the vehicle. This avoids the situation where an undesired operation is performed by inadvertently operating the key. Also, because it is convenient to operate a certain vehicle function within a predetermined distance from the vehicle, such a vehicle function can be operated within the predetermined distance. When the operations for the vehicle functions are limited, the operations for all or some of the vehicle functions may be prohibited in Publication No. 7-59165 and in the invention.
However, Publication No. 7-59165 does not describe how the user could execute any controls in the event that the user leaves the key in the vehicle. It would be expected that if the user leaves the key in the vehicle, the operation of the door lock cannot be executed by remote control in the remote control apparatus. As such, the doors may remain unlocked.
Remote control systems in which a vehicle function such as locking/unlocking doors can be remotely controlled using a portable device via a predetermined service center have been proposed. With the remote control systems, a vehicle function such as locking/unlocking the doors can be remotely controlled without using the keyless entry system.
In the majority of such remote control systems, if the vehicle is occupied, the remote control of a vehicle function by the portable device is not permitted. This is because the remote control presumably does not need to be performed using the portable device, and execution of the remote control would likely startle the occupant of the vehicle. However, the presence of an occupant in the vehicle is commonly determined based on whether the key of the keyless entry system responds to a predetermined radio signal. Thus, if the user leaves the key in the vehicle, it is determined that the user is present in the vehicle. Consequently, remote control of the vehicle function by the portable device is not permitted. Accordingly, for example, the doors may remain unlocked, and the door locking function cannot be remotely controlled using the portable device.